Aberrant spindle position in cells arrested with GTP-Cdc42 concentrated in the bud. (A) Representative time-lapse images showing normal spindle position in a wild-type cell. Numbers indicate time in minutes from the initial polarization of Cdc42 in G1. Scale bar, 5 µm. (B and C) Representative images showing spindle migration to the bud in cells arrested in S phase (B) and M phase (C). Scale bars, 5 µm. (D) Percentage of cells in which the spindle migrated in the bud (n = 100 cells from three experiments).